This invention relates generally to an assembly for the connection of large excavation teeth to the shovel or dipper bucket of large excavation equipment. More particularly, this invention relates to an assembly for securing a large excavation tooth which utilizes a single flex pin to connect the tooth to the excavating equipment on which the excavation teeth are closely spaced.
During the course of large ground excavation projects, it has been found that it is preferable to make the excavation teeth a separate and distinct part, readily attachable and detachable to the main excavation implement, rather than forming the excavation teeth integrally with the main implement. This allows for easy replacement of individual teeth should a tooth become broken or dull.
Traditionally, the excavation tooth has a hollow interior portion which fits onto a nose piece which is integrally formed with the main implement. Pin means are thrust through an orifice in the excavation tooth and through a channel in the nose piece to retain the tooth in position on the nose piece. Because of the tremendous pressure which is exerted upon the tooth during excavation, it is desirable to displace the pin transversely to the excavation movement, which is normally and primarily in the vertical direction. Parallel placement of the pin allows the pin to wobble under the force generated by the excavation implement. This wobble causes early failure of the pin causing the tooth to drop off.
Until fairly recently, a simple arrangement involving a single horizontally displaced pin was sufficient. Now, however, the excavation implements are utilizing closely spaced teeth, thereby making it difficult, and in some instances impossible, to displace the traditional horizontal pin within the excavation tooth. Therefore, there existed a need in the art for a locking assembly whereby the excavation tooth may be engaged and disengaged by working vertically.
Another problem has been encountered with devices of this type which stems from the fact that the nose piece of the implement can become worn so that there is not a precise fit between the tooth and the nose piece. This allows for some horizontal movement of the tooth on the nose piece as well as some vertical or rotational movement of the tooth with respect to the nose piece. A solution to these problems is found in applicant's co-pending application, Ser. No. 200,396 filed Oct. 24, 1980, and entitled "Method and Device for Attaching Excavation Teeth," now abandoned and refiled on Nov. 1, 1982, as continuation-in-part application Ser. No. 438,512, now abandoned. Therein applicant developed a three-pin assembly which successfully held the tooth on the nose pin in a snug fit providing both horizontal and vertical stability while facilitating removal of a single excavation tooth in a group of closely aligned teeth. However, the assembly disclosed therein requires the implementation of both a vertical and horizontal channel extending through the tooth and the nose piece. When utilizing such an assembly on the larger shovels and buckets wherein each tooth weighs approximately 145 lbs., the manufacture of the teeth with the perpendicularly disposed channels extending therethrough becomes a difficult and expensive process. It was therefore deemed highly desirable to develop an assembly for such larger teeth which provided the same securement and replacement features found in the three-pin assembly, but which obviated the need for two transverse channels extending through the teeth and tapered portions of the nose piece. The single pin assembly disclosed herein accomplishes that objective.